package lib.self.util.encrypt;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * description: MD5加密工具类
 * author: Steven Xiao
 * date: 2017/5/25
 */
public class MD5Utils {

    /**
     * 利用MD5进行加密
     *
     * @param text
     * @return 返回值为小写
     */
    public static String getMD5(String text) {
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            md.update(text.getBytes());
            byte b[] = md.digest();

            int i;

            StringBuffer buf = new StringBuffer();
            for (int offset = 0; offset < b.length; offset++) {
                i = b[offset];
                if (i < 0)
                    i += 256;
                if (i < 16)
                    buf.append("0");
                buf.append(Integer.toHexString(i));
            }
            //32位加密
            return buf.toString();
            // 16位的加密
            //return buf.toString().substring(8, 24);
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 将MD5值转换成大写
     *
     * @return
     */
    public static String getMD5UpCase(String text) {
        return getMD5(text).toUpperCase();
    }


}
